A system for monitoring a sensor or switch for operation is disclosed. The switch or sensor is coupled to a CELLEMETRY transmitter for sending electronic serial numbers (ESNs) encoded with information, and receiving mobile identification numbers (MINs), also encoded with information, in accordance with the CELLEMETRY protocol. A microprocessor controls operation of the combination of the radio and sensor or switch. A computerized control center coupled to the Internet provides a connection medium between the cellular system and the control center. When a sensor or switch so connected operates, the radio sends an ESN via the control channels of the cellular system to the Internet, where the ESN is relayed to the control center. There, processing occurs that provides notification to an entity associated with the sensor or switch. Communications from the control center to the radio associated with a sensor are via MIN numbers, and may initiate operation of a device coupled to the sensor.